A systematic outbreak investigation of SARS-CoV-2 transmission clusters in a tertiary academic care center.

BACKGROUND: We sought to decipher transmission pathways in healthcare-associated infections with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) within our hospital by epidemiological work-up and complementary whole genome sequencing (WGS). We report the findings of the four largest epidemiologic clusters of SARS-CoV-2 transmission occurring during the second wave of the pandemic from 11/2020 to 12/2020. METHODS: At the University Hospital Basel, Switzerland, systematic outbreak investigation is initiated at detection of any nosocomial case of SARS-CoV-2 infection, as confirmed by polymerase chain reaction, occurring more than five days after admission. Clusters of nosocomial infections, defined as the detection of at least two positive patients and/or healthcare workers (HCWs) within one week with an epidemiological link, were further investigated by WGS on respective strains. RESULTS: The four epidemiologic clusters included 40 patients and 60 HCWs. Sequencing data was available for 70% of all involved cases (28 patients and 42 HCWs), confirmed epidemiologically suspected in house transmission in 33 cases (47.1% of sequenced cases) and excluded transmission in the remaining 37 cases (52.9%). Among cases with identical strains, epidemiologic work-up suggested transmission mainly through a ward-based exposure (24/33, 72.7%), more commonly affecting HCWs (16/24, 66.7%) than patients (8/24, 33.3%), followed by transmission between patients (6/33, 18.2%), and among HCWs and patients (3/33, 9.1%, respectively two HCWs and one patient). CONCLUSIONS: Phylogenetic analyses revealed important insights into transmission pathways supporting less than 50% of epidemiologically suspected SARS-CoV-2 transmissions. The remainder of cases most likely reflect community-acquired infection randomly detected by outbreak investigation. Notably, most transmissions occurred between HCWs, possibly indicating lower perception of the risk of infection during contacts among HCWs.

Prevalence and Characterisation of Severe Left Ventricular Hypertrophy Diagnosed by Echocardiography in Hypertensive Patients.

BACKGROUND: Arterial hypertension (AHT) is the leading preventable cause of death worldwide. Left ventricular hypertrophy (LVH) is one of the most important prognostic markers in hypertension and a predictor for mortality. The goals of this study were to examine the prevalence of LVH detected by echocardiography in patients with AHT and to describe patients with severe LVH. METHODS: This is a retrospective monocentric study including patients treated at a tertiary hypertension clinic. Echocardiographic data were taken from written reports from our hospital's echocardiography laboratories. We compared patients with severe LVH (septum thickness ≥ 15 mm) with patients with normal left ventricular (LV) geometry and with patients with concentric or eccentric hypertrophy regarding age, gender, comorbidities, medication, duration of hypertension, blood pressure (BP) and ECG changes at time of echocardiography. RESULTS: Twenty-nine patients (7.3%) out of four hundred patients showed severe LVH and one hundred and eighty-nine (47.3%) a normal geometry. In comparison to patients with normal geometry, patients with severe LVH were more likely to be male, older, and with more uncontrolled BP, especially regarding asleep values, multi-drug antihypertensive treatment and comorbidities. In comparison to patients with concentric or eccentric hypertrophy, patients with severe LVH had a significantly higher diastolic BP in the 24 h mean, awake and asleep values. A positive Sokolow-Lyon index did not predict LVH. However, patients with severe LVH were more likely to have T-wave-inversions V4-V6 in at least one lead. CONCLUSIONS: More than half of the patients with AHT have an abnormal geometry in our study (52.5%) and 7.3% a severe LVH. Patients with severe LVH have more often an uncontrolled AHT than patients with a normal LV geometry, despite more antihypertensive treatment. The Sokolow-Lyon index seems to be insufficient to detect LVH.